The present invention relates to a two piece intraocular lens, and more particularly to an artificial intraocular lens for implantation in an eye, such as in the posterior chamber, after extracapsular removal of the natural eye lens, wherein the two pieces are independently successively inserted through a minimum size incision into the eye for assembly therein to form the two piece lens, and include an oblong lens body or optic and a separate ring shaped collapsible tension frame therefor which contains light masking means for inhibiting light rays directed toward the outer edge portions of the lens body from being scattered thereby toward the retina after the assembled lens has been implanted in the eye.
For treatment of conditions such as natural eye lens cataracts, a known eye surgery procedure is to remove the cataracted lens through a minimum size incision in the wall of the cornea of the eyeball, and replace it by an artificial intraocular lens as an internal implant lens. One specific surgical procedure involves the extracapsular removal of the natural eye lens, leaving portions of the posterior lens capsule intact to serve as a positioning site for the intraocular lens to be implanted in the eye.
U.S. Pat. No. 4,605,409 to Kelman discloses a one piece intraocular lens of the above type, having a small size lens body or optic, flexible position fixation haptics, and deformable masking means, such as laterally disposed flat planar wings temporarily contracted to provide the lens with a reduced girth permitting insertion through such a minimum size corneal incision into an eye. Upon implantation, the wings mask the optic side edge portions to overcome the edge glare effect of otherwise scattered incoming light rays at the peripheral marginal regions of the small size lens, such light masking being achieved by leaving the wing surfaces in rough, unground, condition, or by providing an opaque coating thereon.
U.S. Pat. No. 4,056,855 to Kelman shows a two piece intraocular lens, including an elliptically shaped lens member formed of a central lens body or optic and end tongues, and a separate similarly shaped non-collapsible, continuous closed loop wire frame resiliently self-clampable only to the lens body, once the two pieces are independently inserted through a minimum size corneal incision into an eye for like implantation purposes. The frame ends are arranged in the posterior chamber behind the iris and the lens member end tongues are arranged in the anterior chamber in front of the iris, both serving as position fixation means, while the optic is situated across the pupil. No light masking means of the above type are present.
U.S. Pat. No. 4,596,578 to Kelman shows a two piece intraocular lens, including an oblong rectangularly shaped lens body or optic and a separate frame having a similarly shaped noncollapsible split ring formed of cantilever flexible arms for embracingly receiving the optic and also serving as light masking means, and cantilever end limbs as position fixation means, the two pieces being independently inserted through a minimum size incision into the eye for assembly therein. The split ring is needed to permit the flexible arms to be separated for snaking the resulting open ring conformation through the incision and thereafter for enclosing the flexible arms around the optic to assemble the lens prior to implantation.
It would be desirable to provide a minimum size intraocular lens for implantation in an eye, following extracapsular removal of the natural eye lens, permitting rapid and efficient lens insertion through the same minimum size corneal incision used to remove the natural lens, and at the same time provide light masking means for the lens body, while utilizing a structurally simple arrangement of parts, readily fabricated at relatively low cost from widely available materials.